| 摘要 |
PURPOSE:To facilitate maintenance and inspection, by detecting the potential of a shield embedded in an insulation spacer as light by a pair of light emitting diodes connected in parallel in positive and negative opposite relationship to make it possible to easily carry out the positional confirmation of the partial discharge place of the insulation spacer. CONSTITUTION:When rated voltage is charged to a bus bar, a current sufficient to emit light from light emitting diodes 5, 6 is not flowed through a circuit constituted from a condenser 8, a resistor 7 and the light emitting diodes 5, 6. On the other hand, when abnormal voltage with positive polarity is generated relative to the bus bar, voltage is generated in a shield and light is emitted from the light emitting diode 5. When abnormal voltage with negative polarity is generated, light is emitted from the light emitting diode 6. Lights from the light emitting diodes 5, 6 are guided to O/E converters 20, 21 through light guides 18, 19 to be converted to electric signals. Respective electric signals are transmitted to a differential amplifier 22 and, by calculating the difference of the respective electric signals, both positive and negative wave forms are measured and an abnormal place can be detected. |
